RFR(S): 8200387: [Graal] fromTonga/nsk/jdi tests hang with Graal as JIT

[Alex Menkov]

Looks okay to me.

--alex

On 05/24/2018 22:43, serguei.spitsyn at oracle.com wrote:
> Hi all,
> 
> Please, review a fix for:
> https://bugs.openjdk.java.net/browse/JDK-8200387
> 
> Webrev:
> http://cr.openjdk.java.net/~sspitsyn/webrevs/2018/8200387-graal-queue.1/
> 
> Summary:
>    A number of tests are failing when executed with Graal compiler.
>    The issue is that the JDI client event queue becomes overloaded:
> 
>   248     private synchronized void controlEventFlow(int maxQueueSize) {
>   249         if (!eventsHeld && (maxQueueSize > OVERLOADED_QUEUE)) {
>   250             eventController().hold();
>   251             eventsHeld = true;
>   252         } else if (eventsHeld && (maxQueueSize < UNDERLOADED_QUEUE)) {
>   253             eventController().release();
>   254             eventsHeld = false;
>   255         }
>   256     }
> 
>    with the events generated from the Graal compiler execution.
>    As a result, the eventsHeldmode is enabled.
>    The tests hang because the back-end does not get needed commands from 
> the JDI client.
>    Thanks a lot to Igor Veresov for the analysis and suggested fixes!
>    After some discussion we agreed on the work around fix in webrev
>    which is to increase the OVERLOADED_QUEUE value.
> 
>    In fact, the tests have to be fixed as well to filter out the Graal 
> threads posting the events.
>    At this point, fixing of all these tests requires resources but not 
> that critical.
> Now, there is a mess with a relatively big number of the tests failing 
> with different failure modes.
>    The corresponding bugs have already been filed (not sure, all of them).
>    This fix is the first step and a good base for sorting out the rest 
> of the Graal related issues.
> 
>    I've just filed one more Graal bug that was masked other bugs:
> https://bugs.openjdk.java.net/browse/JDK-8203809
>    and suspect, more bugs might be needed to cover all different failure 
> modes.
>    Such bugs should include sub-tasks for including the impacted tests 
> into the ProblemList-graal.
> 
>    A part of the fix is a ProblemList-graal.txt update.
>    Almost all the tests listed in the following Graal related bug 
> stopped failing with the the fix:
> https://bugs.openjdk.java.net/browse/JDK-8195600
>    So, these tests are removed from the ProblemList-graal.
> 
> Thanks,
> Serguei
> 
> 
> 
>